Thermostatic controller.



B. V. EDWARDS.

THERMOSTATIC CONTROLLER APPLICATION FILED MAR. I4. |914.

1,182,000. Patend May 9,1916.

E muv In Verl: tot: by-agvw) IXe/mada Ke WV, M Attys.

UNITED STATES PATENT OFFICE.

BRUCE V. EDWARDS, OF NEWARK, NEW JERSEY, ASSIGNOR. TO EDWARDS ENGINEER-ING- & MANUFACTURING COMPANY, OF NEW YORK, N. Y.. A CORPORATION OF NEWJERSEY.

THERMOSTATIC CONTROLLER.

Application tiled March 14, 1914.

.To all whom t may concern Be it known, that I, BRUCE Vixonx'r Enwxnns,a citizen of the United States, residing at Newark, in the county ofEssex, and State of New Jersey, have invented certain new and usefulImprovements in Thermostatic Controllers, of which the following is aspecification, reference being had therein to the accompanying drawing.

This invention relates to thermostatic controllers or that class ofapparatus operated by temperature changes for operating or otherwisecontrolling alarm systems, sprinkler systems or any other systems.

More particularly. this invention relates to that class of thermostaticcontroller which operates by the volumetric changes of an inclosedfluid, for example, atmospheric air, whose expansion and contraction arethe direct results of heat applied to or detracted from the body of air.

The general objects of the present invention are to aii'ord a moredurable, permanent, efficient, compact. simple and cheap thermostaticcontroller than those heretofore known.

A specific object hereof is to afford a sensitive and durablethermostatic controller of the type wherein operation is caused byrelatively abrupt temperature changes rather than by the actual existingtemperature or by any relatively gradual changes therein. By theseexpressions it will be understood that usually such a therniostaticcontroller is to be self-adjustable so as to avoid operation uponordinary climatic changes or ordinary temperature adjustments within abuilding, whereas for a sudden temperature change, such as the breakingout of a conflagration, the controller will operate to give an alarm,open a water supply or perform other operations.

Other and more Specific objects will be illustrated in the hereinafterfollowing description of a particular embodiment of the presentinvention.

In the accompanying drawings forming a part hereof, Figure 1 is acentral section of a thermostatic controller embodying the presentinvention. For convenience, the apparatus may be considered as attachedto the ceiling of a room, so that the ligure is a vertical centralsection. Fig. l is a plan view partly in section upon the plane 2 2 ofFig. 1. Fig. 3 is an enlarged detail of a portion Specification ofLetters Patent.

Patented May 9, 1916.

Serial No. 824,645.

of Fig. 1. Fig. 4 is a modified embodiment showing a normally closedinstead of a normally open electric controlling circuit. Fig. 5 is amodification as to the form of the expansion chamber.

Similar reference numerals designate corresponding parts in the severalfigures.

In order to inclose a body of air an air chamber is provided in anapparatus of this kind. This is in effect a fluid-expansion chambersince the operation of the device is due to volumetric expansion orcontraction of the fluid in the chamber. In connection therewith isprovided some suitable control device operated by volumetric changes ofthe fluid due to temperature changes outside the chamber, and thisdevice may, for convenience, be illustrated as taking the form of anelectric contact device, which affords delicate and easily regulatedcontrol, although mechanical and other forms of control device couldobviously be used. .Xpparatuses of this general nature have been alreadyknown and it has already been suggested to provide a restricted airescape permitting air to How to and fro from or into the chamber forequalizing the interior and exterior pressures due to gradual volumetricchanges. For example, the rigid wall of the air chamber of the expiredpatent 370,851 of October 4, 1887. is capable of permitting the slowpassage of air owing to the porous nature of the material. while in theanalogous structure in expired patent 522,97 of July 17. 1894, a smallblock of porous material is incorporated in the chamber wall. These andother expedients tried for the purpose have proven objectionable forvarious reasons including dcstructibility, obstruction or clogging up ofthe escape, necessity for difficult regulation. non-durability.diiiiculty of manufacture or complication of structure.

In the present invention there is provided in connection with the rigidor self-sustaining chamber wall a fluid escape for equaliving gradualvolumetric or pressure changes of `a novel and extremelv simplecharacter, the same consisting of a thin membrane constituting one ofthe chamber walls, the same punctured with a simple. constantlyopenminute aperture. By minute in this connection is meant such a degree ofsmallness as is scarcely visible by the unaided eye, and theaccompanying drawings are neceslil() lill) sarily exaggerated. Indeed.the puncture is preferably of such small size that it would beimpractical to produce excepting in the extremely thin preferablymetallic membrane referred to. The puncture is so small that, whilepermitting passage of air to equalize pressures for ordinary dailytemperature changes. it serves without the need of valve or othermovable part or obstruction of any nature to restrict the air flow thatwould be necessary to equalize pressures in thc case of an abrupttemperature and volume change owing, for instance, to a conflagration.By a thin membrane is meant preferably a sheet of metal. such as copper,of such extreme thinness as to be capable of receiving the minutepuncture referred to and of thus affording an air escape passage havingsubstantially no deA gree of length` but serving to effect restrictiouby the smallness of the puncture. Such a membrane will necessarily be ofa flexible nature if not rigidly mounted in the apparatus. Such an airescape, unlike a porous wall or pad, is free from liability todeteriorate. is simple to construct so as to afford a given restrictionto .air How and is simple and easy to incorporate in the apparatus. Alsothe present air escape is differentiated from a vent-tube which, owingio its substantial length, is subject to clogging and filling up andrequires regulation. Similarly, such air escape is differentiated from.any valve-controlled tube or opening and from any apparatus involvingthe use of screws or other movable parts and, indeed,y from any airescape passage formed in or by any rigid part not having the characterof the thin membrane hereof.

Referring to the drawings, `a substantially rigid hollow casing orchamber wall 10 is shown. This is preferably hemispherical, givingsightlines.. strength and requisite interior volume. 1n connection withthe casing or chamber wall 10 is shown a membrane 11. the two formingbetween them the air expansion chamber 12. Preferably the casing 10 iswholly closed except at the position of the membrane 11, although itmight take various shapes or even have extended arms, branches. tubes orribs. The chamber 12 is full of fluid` preferably air, and the wall 10,while rigid, is sufficiently thin to quicllv transmit heat, so that theinterior air will change volume readily in response to outsidetemperature changes.

The membrane 11 is indicated in an eX- aggerated way as having a minutepuncture at 13, this puncture being constantly open, but of such smallsize as to restrict the air flow therethrough, it serving to equalizeinternal and external pressure excepting upon abrupt temperature andvolume changes.

Owing to the described advantages of this form of air escape. greatsensitiveness is insured and` therefore. the size of the air chamber andthat of the entire apparatus may be materially reduced, thus addingcheapness to simplicity and rendering the apparatus less objectionablyapparent.

A suitable control device, such as the device 11, may be employed, thisbeing adapted to be operated by abrupt temperature changes, so as togive an indication or alarm or set a sprinkler system into operation.The device 1i may be operated by the movement of a flexible diaphragmforming one of the chamber inclosing walls.

AXnother advantage of the present improvement is now perceivable in thatthe punctured membrane before referred to and the controller operatingdiaphragm may be combined into one and the same part. Thus, iu thedrawings the minute puncture 13 is shown formed directly in theextremely thin metallic diaphragm 11, which is movable upon abrupttemperature and volume changes so as to effect the operation of thecrntrol device 14. This result in turn has the further advantage thatthe puncture leads from the air chamber 12 directly into the recess atthe outer side of the diaphragm, this recess, therefore, serving as aprotecting means not only preventing l'nechanical injury to the thindiaphragm but assisting to exclude dirt and moisture from access to thepuncture. By recess is meant a space not entirely closed, but having afree communication to atmosphere. By chamber, on the contrary, is meanta substantially closed space lacking any free inflow and outflow.

It is found that the extremely thin copper membrane, when punctured.forms a durable air escape and is not subject to corrosion or otherdeterioration, especiallyv when mounted in the protected mannerdescribed.

The device 14 may be. one of two electrical contacts, the other, forconvenience, consisting of the diaphragm 11. As shown in Fig. 1. anabrupt temperature rise owing to a conlagratiou will swell outward thediaphragm 11 beyond the capability of the air escape 13 to equalizepressures and thus cause contact between the diaphragm 11 and contact14, so as to close a controlling electric circuit.

Having described the more important features of construction andoperation, the preferred details of structure will now be described.

Support for the described elements. 10, 11, 12. 13 and 14, may besuitably provided, for example by a frame shown in the form of acircular plate 15. It is desired that there shall be no accumulated airpressure outside the diaphragm 11 to impede its movement, and frame 15is therefore formed with an unrestricted fluid aperture 16 leading fromthe space between the frame and the diaphragm to the externalatmosphere. The

il t) IBO aperture 1G is shown far removed from the position of thepuncture 13 so as to minimize the possibility of foreign matter reachingthe puncture; and, as will be hereinafter seen, this possibility isfurther taken care of by totally excluding entrance of foreign matter.The circular frame plate 15 is shown as detachably supported from awooden base or fixture 18, namely, by means of a peripherally flangedlock plate 19, permanently mounted on the base 18, and a pair of pins onthe frame piece 15, the heads of such pins adapted to be engaged withand disengaged from keyhole slots 21 in the lock plate 19 and such slotshaving offset edges 22 tending to wedge and thereby more surely preventaccidental detachment.

Instead of attaching the punctured movable diaphragm directly to theconvex shell or casing 10, it is preferred to attach both of them to theframe plate 15 whereby, on detaching the shell, the interior is openedto access and inspection, and the greatest efiiciency of mounting of theparts is secured.

The casing or shell 10 may be connected to the frame plate 15 asfollows. The two are shown circular so that they may bc engaged by screwthreads permitting easy disengagement, yet solid, permanent and airtightattachment. To this end the casing has secured or soldered within it anannular threaded and flanged ring 24. Beyond or above the ring 24 theshell 10 is continued in he form of an extension Z5 substantiallymeeting and contacting the base 18, thus inclosing a circular space orrecess between the base and the frame plate` An unrestricted opening 26is provided in the eX- tension 25, this opening cooperating with theopening 16 in the frame plate, so as to give free Communication betweenthe atmosphere and the recesses above the diaphragm. It will be notedthat moisture or foreign matter, in order to reach thc puncture 13` mustpass through the tortuo-ns course from the opening 26 entirely acrossthe recess between the frame and base, thence through the opening 16 inthe frame and thence entire-ly across the recess between the frame anddiaphragm. Thus very effective protection to the diaphragm and punctureis afforded.

The diaphragm mav be mounted upon the frame plate bv means of an annulardownward flange 2.7 formed on the latter in connection with a lockingring or cap 28 which` in the process of assembling the parts. is forcedover the frame flange, so as to stretch and tightlv secure the diaphragmbetween them.y aided bv the application of' cement if desired. Forconvenience. the puncture 13 may be located near one marginal edge ofthe diaphragm. as shown. and, in order that thc locking cap 28 may in nowav obstruct its action, a substantial opening 29 may be formed, asshown, in the locking cap opposite the puncture. The puncture, which maybe formed by means of an extremely minute needle, may be produced afterthe assemblage of the parts 15, 11, and 28 by inserting the needlethrough the opening 29.

The locking ring or cap 28 is not intended to in an;y way affect airmovements, and its central portion may have a large opening 30 oppositethe central portion of the diaphragm. Owing to the diaphragm beingconnected to the downward flanges of the frame plate, the recess beforereferred to is constituted between the diaphragm and frame plate.

The. control device referred to may be convenicntlv supported upon theframe plate 15, as follows. The flanged and threaded central opening ofthe frame plate 15 mai' have engaged within it an insulating bushing 32,also interiorly threaded and engaged within it bv a sleeved block 33,which is ccntrallv bored and threaded to receive the adjustable contactdevice 14. i'ccording to the degree of responsiveness desired, the screwcontact 14 may be adjusted nearer to or farther from the metallicdiaphragm 11.

At the upper part of the block 33 is a wire recess -34 cooperating witha binding screw so as to secure an electrical conductor in circuit withthe contact 14.

To complete the circuit a binding screw 37 mav be provided on the frameplate 15; a conductor 40 from the binding screw 35 and a conductor 41from the binding screw 37 leading, for example. to a battery 42 andalarm 43, conventionally7 indicated as representing ani7 formof'apparatus or system controlled bv the control device 14.

Since it is sometimes preferred to maintain a normally closed ratherthan an open electric circuit, a simple modification for that puri nseis indicated in Fig. 4, wherein the control device 14 is replaced by acontrol device 44 differing from the former in having a disk 45 at itslower end adapted to be raised and lowered by adjustment and adapted tobe normally contacted at the upper side of its peripherv bv an invertedcontact 46 projecting hook-like from the diaphragm 11. iVith thisarrangement, upon abrupt temperature and pressure increase` thediaphragm lifts the contact 46 .from the disk 45, thus breaking thecircuit and thus, forexample. releasing a magnetically held armature.whose fall sets suitable alarms or other devices into operation.

It has alreadv been explained how the volume of the air chamber 12 isreduced in size owing to thc advantageous nature of the combineddiaphragm and air escape; and the size maivv be still further reducedand the same responsiveness maintained by constituting the hemisphericalcasing or shell l0 out of corrugated metal. Thus, in Fig. 5, is shownsuch a casing having the corrugations 49, which not only increase thesurface for transmission of exterior heat, but also give added strengthto the shell against injury7 or distortion.

It will thus be seen that thermostatic controllers have been illustratedand described embodying the principles and attaining thc objects andadvantages before set forth and other advantages pertaining to thedescribed structures will be apparent to those skilled. in the art.

Since mamv matters of arrangement, design, detail and other features maybe variousl \7 modified without departing from thel novel principlesinvolved, no limitation to such features is intended excepting so farset forth in the appended claims.

What is claimed is:

l. A thermostati-:f controller including in combination a hollow shell,a diaphragm forming with said shell an expansion chamber, a frame havinga free opening and formV ing with said diaphragm a protective recess, abase spaced from said frame, a shell extension having a free opening andforming with said frame and hase a second protective recess, and acontrol device operated by diaphragm movement upon volumetric change insaid chamber, said diaphragm formed with a constantly-open butrestricted pressure-equaliziug aperture, .vli'ereby only abrupttemperature changes are effective to operate said control device.

2. A thermostatic controller including in combination a base and ahollow shell, the two concealing all of the following elements, ayminutely punctured thin diaphragm spaced from said base and forming withsaid shell an expansion chamber, and a control device between base anddiaphragm operated by diaphragm movement upon volumetric change in saidchamber, a frame forming a mutual connecting means between said base,shell, diaphragm and control device.

3. A thermostatic controller including in combination a base and ahollow shell, the two concealing all of the following elements, apunctured diaphragm spaced from said hase and forming with said shell anexpair sion chamber, and a control device between base and diaphragmoperated by diaphragm movement upon volumetric change in said chamber, aframe forming a` mutual connecting means between said base, shell,diaphragm and control device, and said frame and shell having separatedfree openings.

4. A thermostatic controller including in combination a rigid corrugatedheat-trans mitting convex shell, a flexible diaphragm closing the sameand a control device oper" ated by diaphragm movement.

5. A thermostatic controller including a frame, a hollow shell, adiaphragm, and a control device, combined as follows: said shell anddiaphragm arranged to inclose an expansion chamber, said diaphragm andframe arranged to form a diaphragm protecting recess, said frame formedwith an unrestricted opening into said recess, said diaphragm formedwith a constantly-open but restricted pressuieequalizing aperture, andsaid control device arranged to be operated by movement of saiddiaphragm upon volumetric change in said chamber due to abrupttemperature changes.

6. A thermostatic controller including a. frame, a hollow shell. adiaphragm, and a control device, combined as follows: said shell anddiaphragm arranged to inclose an expansion chamber, said diaphragm andframe arranged to form a diaphragm protecting recess, said frame formedwith an unrestricted opening into said recess, said diaphragm formedwith a constantly-open but restricted pressurefequalizing aperture, saidshell having an extension forming with said frame a second recessconstantly freely open to the atmosphere and said control devicearranged to be operated by movement of said diaphragm upon volumetricchange in said chamber duc to abrupt temperature changes` 7. Athermostatic controller including a base, a frame, a hollow shell, adiaphragm, and a control device, combined as follows: said shell anddiaphragm arranged to inclose an expansion chamber, said diaphragm andframe arranged to form a diaphragm protecting recess, said frame formedwith an unrestricted opening in said recess, said diaphragm formed witha constantly-open but restricted pressure-equalizing aperture be tweensaid chamber and recess, said shell having an extension extending tosaid base and forming with said base and frame a second recess, andhaving an unrestricted opening between said second recess andatmosphere, and said control device supported on said frame and arrangedto be operated by movement of said diaphragm upon volumetric change insaid chamber due to abrupt temperature changes.

ln testimony whereof I aflix my signature in presence of two witnesses.

BRUCE V. EDlVARDS.

Witnesses:

EUGENE F. BAEnnxnon'r, HERBERT DIXON.

Copies of this patent may be obtained foi` five cents each, byaddressing the Commissioner o! Patents, Washington, D. C.

